Tandem axle spring suspension



HQ.Z.

March 8, 1949. w, JONKHOFF 2,463,627

TANDEM AXLE sgnme SUSPENSION Original Filed May is, 1944 l 2Sheets-Sheet 1 Hwl; whzwr March 8, 1949. H. w. JONKHOFF 2,463,627

TANDEM AXLE SPRING SUSPENSION Original Filed May 15,, 1944 2Sheets-Sheet 2 522x17; WJOnflcOff Patented Mar. 8, 1949 TANDEM AXLESPRING SUSPENSION Henri W. J onkhoff, New York, N. Y.; Ainsworth B.Blood and Stanleigh P. Friedman executors of said Henri W. J onkhofi,deceased Original application May 15, 1944, Serial No.

535,669. Divided and this application November 21, 1944, Serial No.564,630

5 Claims. 1

My invention provides a new form of laminated spring on which themaximum working sphere, instead of at the extremities of the main blade,now is shifted to the center part of the spring so as to reduce theamount of material involved in movement.

My invention consists of a laminated spring in which the main bladeforms the core from end to end, its extremities fixed to differentbases, while supporting blades, or other stiifening means, arepositioned on the top and bottom faces of said core and extend from theextremities of the spring in aligned pairs toward the middle part of thecore or main blade where they are positioned separate from each other.

The invention may be embodied in several combinations in which the mainblade always forms the core from end to end. This core takes up thestresses between the different bases of the spring ends, thus forming areal connection and meanwhile allows for more base to which the springmay be attached between said extremities.

Because the core of the main blade can remain uncovered by auxiliaryblades at any point at will, the fulcrum for the next base of the springcan be chosen, thus reducing the wave of movement in regard to thefulcrum of the laminated spring.

Stops may be provided to prevent overloading of the main blade whichlimit the vertical movement of the free ends of the spring.

This application is a division of my application filed May 15, 1944,Serial No. 535,669.

In the drawing:

Figure 1 is a side elevation of a truck illustrating my improved spring.

Figure 2 is a side elevation of the spring detached.

Figures 3, 4 and 5 are detail side elevation views illustrating thepossible actions of the core of the spring.

My improved laminated spring comprises a continuous blade extending fromend to end of the spring. At the middle portion of the blade I arrangesubsidiary blades 2 and 3, above and below the blades I and I interposea blade 4 between the blades 3 and I which is shorter than the blades 3,thereby leaving a space 5 between the blades I and 3. The blades I, 2,3, 4 are clamped together by the shackles 6. On the end portions of thecore blade I I secure by means of the shackles I a plurality ofsubsidiary blades 8 and 9 and insert a blade I between the blades 8 andthe core blade I, this blade II! being comparatively longer than theblades 8 and 9 and designed to enter and slide in the space between theblades 3 and core blade I as shown in the drawings. It will be seen fromthe drawings that there is normally a space II between the inner ends ofthe blades 2, 3, 8 and 9.

The usual type of spring now used in heavy vehicles is very clumsy,heavy and costly, whereas my invention aims at a more economicalapplication of spring blades so as to save material and reduce weightand costs. Therefore, the inner base type suspension of springs ispresented, whereby under similar conditions, the amount of actionrequired from the spring elements is greatly reduced. As illustrated inthe drawings, this action of the spring I now takes place in the mainblade I, far inside the wheel base, somewhere midway between the springseat and the wheel axle I2, which in the drawing is carried on a rigidextension of the spring. Said extension acting as a lever, allowing foraggravated vertical movement of the wheel axle at its outer end relativeto the length of the extension, so that vertical movement of the wheelcan be kept normal, meanwhile reducing the length and the weight of thespring materially.

As will be seen in the drawings, the blades of the laminated spring areassembled in such a way that only one blade I in the middle forms athrough uninterrupted connection between the frame and the wheelcarrying arm I l, allowing for a limited flexibility at point I I.Furthermore, in the drawings it will be seen that the central main bladeI, above and below, is supported by other spring blades except for thecomparatively short free distance at point II, where the main blade I issupported underneath only by a blade Ill based on the wheel arm andextending between the main blade I and the minor blade 3, so that it canslide between the two blades and allow for bending at point II. The useof such secondary spring blades may be multiplied; for instance, anotherone may be placed on the top of the main blade I to add resistanceagainst deformation of the main blade I and so as to counterbalance theeifect caused by the application of brakes.

Inasmuch as the core of the main blade can remain uncovered by auxiliaryblades at any point at will, the fulcrum for the next base of spring canbe chosen, thus reducing the wave of movement in regard to the functionof the present laminated springs.

In case there is need for an increase of the capacity of the spring,some of the pairs of auxiliary spring blades can be made of differentlength in such a way that the space between the two blades does notcoincide with the original uncovered part of the main blade, but thatthe longer one of the pair overlapping and sustains the free part. Suchoverlapping blade must be allowed to slide between the main and the nextauxiliary blade when under load. In using this arrangement the capacityof the spring, instead of being bound to the strength of the main bladeonly, now can be doubled or trebled without interfering with theprinciple of my invention or with determined place where the bending hadto take place, so long as the main blade forms the uninterrupted core ofthe spring from end to end.

From the drawings it will be seen that one of the middle supportingblades is shorter than the others, and that one of the end supportingblades is longer than the others, whereby the longer end supportingblade may enter and have a sliding engagement with the middle supportingblades in alignment with the shorter middle supporting blade.

In the heavy vehicles the same principle of the invention can be appliedresulting in a great saving of material, as shown in my patentapplication filed May 15, 1944, Serial Number 535,669.

The usual type of blade spring, now used in vehicles, is very clumsy,heavy and costly, whereas my invention aims at a more economicalapplication of spring blades so as to save material and reduce weightand costs. Therefore, the inner base type suspension of springs ispresented, whereby, under similiar conditions, the amount of action,required from the spring elements, is greatly reduced; meanwhile, thefinal effect on the sprung parts, remaining the same.

The principle of the invention may be clarified by some diagrams. Themiddle part of the main or core blade is fixed to a body A (Fig. 3),which, on account of the free part of the core on either side of thebody, can rock longitudinally (Fig. 4). The amount of rock is limited bymeans of up ward extensions M on the two arms between which the body canmove. In this way, on account of the bending in opposite directions ofthe two free parts of the core, the tipping of the body can becontrolled and be restored to its original position.

In case the body is kept constantly in its original upright position,the two free parts of the core blade do allow for the vertical movementof the extremities of said core arms. Said body may be supported bywheels or by other supporting bases, in which case the body, on accountof its weight, practically drops relative to said support (Fig. 5) andboth extremities of the core blade bend upward. Again in this case thesame stops limit the vertical movement of the arms and protect the coreblade from excessive bending. It does not need further explanation thatthe body, instead of being mounted, may just as well hang and extenddownwards from the core blade.

The device can act as a support on either side of a body and the twodevices then are to be arranged longitudinally and parallel to eachother. The working of each device being independent, the two devices insuch a unit provide for sideward rocking of the body to a limitedextent.

All the aforesaid motions are functions of the invention embodied in thesimple construction as outlined in the figures allowing for an unusualeconomic application of the little material involved.

The invention can be applied in any design in which a body exerts weightpressure to be counteracted by springs. Therefore, it can be applied instationary bodies like furniture or in vehicles between the body and thewheel axles or in the seats so as to absorb shocks.

For light vehicles, such as baby buggies, the invention is especiallyadaptable because the spring flexibility now can be controlled Within acertain range, without the application of heavier or lighter springblades. The invention for this reason provides for a different springaction for which the present spring application offers no substitute.

' forming The application of the invention in any design can be made fitfor the purpose so that all the functions can be performed promptly.

The amount of tipping of the body is to be limited by stops, but theresistance against tipping does not necessarily involve the use of aheavier core spring blade. It can be attained by increasing the width ofthe body attachment to the core blade. Meanwhile, in placing the coreblade in a lower plane than the wheel axle, acting as the fulcrum aroundwhich the tipping takes place, the suspension can be made underslung,which retards the initial momentum of the tipping.

The amount of vertical movement of the extremities of the two armsrelative to the body is limited by the aforementioned stops. But theamount of lift of said extremities merely depends on the length of saidarms, consequently the wheel base of the vehicle.

The weight of a loaded body determines the thickness and the width ofthe core spring blade to be chosen. But an increased load can becounteracted by increasing the effectiveness of the core spring blade.This can be achieved by reducing the length of each free part of thecore blade, which can be accomplished without influencing the totallimit of the movement of the slots.

All this shows that each design has to represent a complete unit inwhich the right proportions of each part are to be considered. They canbe chosen at will so as to meet conditions effectively, thereby using aminimum of material covering a wide scope of requirements.

What I claim is:

1. In a spring construction for supporting the front and rear axles of avehicle truck, the combination, with a truck frame, front and rear wheelcarrying axles, and a load carrying pedestal mounted on the frame at anintermediate point between said axles, of a laminated spring extendinglongitudinally of the frame beneath the pedestal and continuously fromaxle to axle, said spring comprising a main core blade continuous fromend to end of the spring, a set of supporting blades arranged above andbelow the middle portion of the core blade and secured therewith to thebase of the pedestal and forming a central main laminated spring portionof maximum resistance to bending deflection, and a set of supportingblades arranged above and below each end portion of the core blade andsecured thereto and to the axles and with said core blade substantiallycounterpart laminated" end spring portions of substantially likeresistances to bending deflection connecting the main portion of thespring with the respective axles, at least some of the supporting bladesof the end sets being spaced at their inner ends from the ends of thesupporting blades of the middle set at points in front and rear of andin close proximity to the pedestal to provide intervening portions ofmajor resiliency in the length of the spring between said laminated maincentral spring portion and said counterpart laminated end springportions.

2. In a spring construction for supporting the front and rear axles of avehicle truck, the combination, with a truck frame, front and rear wheelcarrying axles, and a load carrying pedestal mounted on the frame at anintermediate point between said axles, of a laminated spring extendinglongitudinally of the frame beneath the pedestal and continuously fromaxle to axle, said spring comprising a main core blade continuous fromend to end of the spring, a set of supporting blades arranged above andbelow the middle portion of the core blade and secured therewith to thebase of the pedestal and forming a central main laminated spring portionof maximum resistance to bending deflection, and a set of supportingblades, of a lesser number than those of the main spring portion,arranged above and below each end portion of the core blade and formingwith said core blade substantially counterpart laminated end springportions of substantially like resistances to bending deflection, andbrackets securing the end sets of supporting blades to the end portionsof the core blade and connecting the ends of the spring with the axles,at least some of the supporting blades of the end sets being, spaced attheir inner ends from the ends of the supporting blades of the middleset at points in front and rear of and in close proximity to thepedestal to provide intervening portions of major resiliency in thelength of the spring between said laminated main central spring portionand said counterpart laminated end spring portions.

3. In a spring construction for supporting the front and rear axles of avehicle truck, the combination, with a truck frame, front and rear wheelcarrying axles, and a load carrying pedestal mounted on the frame at anintermediate point between said axles, of a laminated spring extendinglongitudinally of the frame beneath the pedestal and continuously fromaxle to axle, said spring comprising a main core blade continuous fromend to end of the spring, a set of supporting blades arranged above andbelow the middle portion of the core blade and secured therewith to thebase of the pedestal and forming a central main laminated spring portionof maximum resistance to bendin deflection, a set of supporting bladesarranged above and below each end portion of the core blade and securedthereto and to the axles and forming with said core blade substantiallycounterpart laminated end spring portions of substantially likeresistances to bending deflection connecting the main portion of thespring with the respective axles, at least some of the supporting bladesof the end sets being spaced at their inner ends from the ends of thesupporting blades of the middle set at points in front and rear of andin close proximity to the pedestal to provide intervening portions ofmajor resiliency in the length of the spring between said laminated maincentral spring portion and said counterpart laminated end springportions, stop members projecting upwardly from the ends of the springat opposite sides of the pedestal, and coacting stop members on thepedestal and frame for limiting the movements in opposite directions ofthe first-named stop members.

4. In a spring construction for supporting the front and rear axles of avehicle truck, the combination, with a truck frame, front and rear wheelcarrying axles, and a load carrying pedestal mounted on the frame at anintermediate point between said axles, of a laminated spring extendinglongitudinally of the frame beneath the pedestal and continuously fromaxle to axle, said spring comprising a main core blade continuous fromend to end of the spring, a set of supporting blades arranged above andbelow the middle portion of the core blade and secured therewith to thebase of the pedestal and forming a central main laminated spring portionof maximum resistance to bending deflection, a set of supporting bladesarranged above and below each end portion of the core blade and formingwith said core blade substantially counterpart laminated end springportions of substantially like resistances to bending deflection,brackets securing the end sets of supporting blades to the end portionsof the core blade and the ends of the spring to the axles, at least someof the supporting blades of the end sets being spaced at their innerends from the ends of the supporting blades of the middle set at pointsin front and rear of and in close proximity to the pedestal to r provideintervening portions of major resiliency in the length of the springbetween said laminated main central spring portion and said counterpartlaminated end spring portions, stop members projecting upwardly from thebrackets to points at opposite sides of the pedestal, and coacting stopmembers on the pedestal and frame for limiting the movements in oppositedirections of the first-named stop members.

5. In a spring construction for supporting the front and rear axles of avehicle truck, the combination, with a vehicle body, a truck frame, andfront and rear wheel carrying axles, of a load carrying pedestalswiveled at its upper end to the vehicle body and fixed to the frame atan intermediate point between said axles, a laminated spring extendedlongitudinally of the frame beneath the pedestal and continuously fromaxle to axle, said spring comprising a main core blade continuous fromend to end of the spring, a set of supporting blades arranged above andbelow the middle portion of the core blade and secured therewith to thebase of the pedestal and forming a central main laminated spring portionof maximum resistance to bending deflection, a set of supporting bladesarranged above and below each end portion of the core blade and formingwith said core blade substantially counterpart laminated end springportions of substantially like resistances to bending deflection,brackets securing the end sets of the supporting blades to the endportions of the core blade and the ends of the spring to the axles, atleast some of the supporting blades of the end sets being spaced attheir inner ends from the ends of the supporting blades of the middleset at points in front and rear of and in close proximity to thepedestal to provide intervening portions of major resiliency in thelength of the spring between said laminated main central spring portionand said counterpart laminated end spring portions.

HENRI W. J ONKl-IOFF.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 63,330 Stuart Mar. 26, 18671,166,615 Mason et a1 Jan. 4, 1916 1,623,422 Lovejoy Apr. 5, 192"!2,021,306 Hathorn Nov. 19, 1935 2,188,909 Leighton Feb. 6, 1940 FOREIGNPATENTS Number Country Date 541,215 Germany Jan. 12, 1933 710,953 FranceJune 16, 1931

